Comparison of the Load at Fracture of Turkom-Cera to Procera AllCeram and In-Ceram All-Ceramic Restorations

Purpose: This study investigated the occlusal fracture resistance of Turkom-Cera-fused alumina compared to Procera AllCeram and In-Ceram all-ceramic restorations.
Materials and Methods: Six master dies were duplicated from the prepared maxillary first premolar tooth using nonprecious metal alloy (Wiron 99). Ten copings of 0.6 mm thickness were fabricated from each type of ceramic, for a total of thirty copings. Two master dies were used for each group, and each of them was used to lute five copings. All groups were cemented with resin luting cement Panavia F according to manufacturer's instructions and received a static load of 5 kg during cementation. After 24 hours of distilled water storage at 37°C, the copings were vertically compressed using a universal testing machine at a crosshead speed of 1 mm/min.
Results: The results of the present study showed the following mean loads at fracture: Turkom-Cera (2184 ± 164 N), In-Ceram (2042 ± 200 N), and Procera AllCeram (1954 ± 211 N). ANOVA and Scheffe's post hoc test showed that the mean load at fracture of Turkom-Cera was significantly different from Procera AllCeram ( p < 0.05). Scheffe's post hoc test showed no significant difference between the mean load at fracture of Turkom-Cera and In-Ceram or between the mean load at fracture of In-Ceram and Procera AllCeram.
Conclusion: Because Turkom-Cera demonstrated equal to or higher loads at fracture than currently accepted all-ceramic materials, it would seem to be acceptable for fabrication of anterior and posterior ceramic crowns.     

Evaluation of glass ionomer luting cements

Abstract – In the present study the three glass ionomer luting cements available on the Scandinavian market in June, 1982 were evaluated by comparison with a zinc phosphate and a zinc carboxylate cement. The following properties were tested: effective maximum grain size, retention, strength, bond strength to dentin, disintegration in and absorption of water and solubility in 0.001 n lactic acid. The glass ionomer cements proved to be fully acceptable luting materials.     

Clinical evaluation of Procera AllCeram crowns in Japanese patients: results after 5 years

Summary  Procera AllCeram crowns were prospectively evaluated clinically in both anterior and posterior regions in Japanese. One-hundred and one crowns were fabricated for 57 patients at the Tsurumi University Dental Hospital from August 2001 to October 2002 and evaluated according to the California Dental Association (CDA) quality evaluation system at baseline and annually at all follow-up examinations for 5 years. The plaque index (PI) and gingival index (GI) were recorded, and chipping and fracture were checked at the same time as well. A total of 75 Procera AllCeram crowns were evaluated, and the cumulative survival rate was 90·2% over the 5-year clinical trial. Six crowns experienced fractures within the veneering porcelain and from aluminium oxide coping, all of which occurred on the premolar and molar regions, and they had to be removed. Small chipping was observed on three crowns. According to the CDA criteria, 98% of Procera AllCeram crowns were rated as satisfactory, and PI and GI were comparable to those of control teeth during the observation period.     

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目的比较修复临床常用的9种黏结材料与传统的磷酸锌水门汀对金属全冠固位力的影响。方法2008年1—12月在大连市口腔医院选用90颗完整的双尖牙经包埋固位后,用车床进行牙体预备。使预备后的牙体保持4mm的临床冠高度,20mm的临床冠周径。用失蜡铸造法完成金属全冠制作。用不同的黏结材料黏固金属全冠,用万能实验机检测金属全冠的固位力。经方差分析,比较不同黏结材料对金属全冠固位力的影响。结果本研究使用的黏结材料与传统的磷酸锌水门汀相比,对金属全冠固位力的影响存在显著的差异(P<0.01),不同黏结材料对金属全冠固位力的影响也有显著性差异(P<0.05)。结论不同种类的黏结材料对金属全冠固位力的影响存在差异,修复临床应根据不同的临床情况选择不同的黏结材料。     

The retentive effects of pre-fabricated posts by luting cements

The purpose of this study was to compare the retention of two different pre-fabricated posts cemented to the root canal with four different adhesive luting cements and a zinc phosphate cement. The crowns of 100 freshly extracted human mandibular central and lateral incisors were removed at the cementoenamel junction and divided into two main groups (A = ParaPost and B = Flexi-Post) and further divided into five subgroups to evaluate the effects of five different cements (Rely-X ARC, Panavia F, ParaPost Cement, Flexi-Flow Natural and Adhesor) each with 10 samples. Post-holes were prepared on all of the roots following the manufacturer's instructions. Each sample was placed into a specialized jig and tensile strength tests performed by using testing machine with a crosshead speed of 0.638 cm min(-1) and force applied until failure. The data were analysed with one-way anova (Post Hoc a Scheffe's S test) and two-way anova (P < 0.001). The Flexi-Post dowels had a mean of 54.21 kg (s.d. = 9.37) and demonstrated statistically higher retention than ParaPost dowels with a mean of 33.93 kg (s.d. = 10.69) for all of the cement groups (P < 0.001). In Flexi-Post and ParaPost dowel groups; Rely-X ARC was statistically higher than the Panavia F, ParaPost Cement, Flexi-Flow Natural and Adhesor (P < 0.05). Adhesor was significantly lower than the other subgroups (P < 0.05). Resin luting cements have demonstrated very high tensile strength potential for a strong bond to dentin.     

不同粘接剂及表面处理对氧化锆的粘接强度的影响

目的:评价不同粘接剂及表面处理方法对氧化锆陶瓷与粘接剂的粘接强度的影响.方法:将较大氧化锆瓷片和较小氧化锆瓷片派对,随机分成12组,每组10对.粘接剂选用Ketac Cem Easymix、Rely X luting、Bifix QM和Panavia F,对氧化锆的表面分别喷砂、硅烷化或喷砂联合硅烷化处理,并进行剪切粘接强度测试.结果:在使用Ketac Cem Easymix和Rely X luting时,喷砂提高了粘接强度(P＜0.01).在使用Bifix QM和Panavia F时,喷砂、硅烷化或喷砂联合硅烷化处理提高了粘接强度(P＜0.01).表面处理相同时,Panavia F与氧化锆的粘接强度高于其它粘接剂(P＜0.01).结论:使用Panavia F联合喷砂加硅烷化处理的粘接强度最高.     

Fracture resistance of crowned incisors with different post systems and luting agents

This study evaluated the fracture resistance of crown-restored incisors with different post-and-core systems and luting cements. Fifty intact maxillary central incisors were randomly assigned to five groups of 10 teeth each. Group 1 was restored with fibre posts (Snowpost) luted with an adhesive composite resin cement (Panavia F). Group 2 was restored with titanium alloy posts (Parapost) luted with the resin cement, and Group 3 with titanium alloy posts and a glass-ionomer cement (Fuji I). Composite cores (Clearfil Photocore) were built up in groups 1, 2 and 3. Group 4 was restored with cast post-and-cores luted with the resin cement, and group 5 with the cast post-and-cores and the glass-ionomer-cement served as a control group. All teeth were restored with metal-ceramic crowns. After thermal stressing, the specimen was then secured in a universal testing machine. Fracture loads and modes were recorded. One-way ANOVA and a Tukey test were used to determine significant differences between the failure loads of groups. Chi-square test was conducted for evaluation of the fracture modes. The fracture loads of groups 1 and 2 were significantly higher than that of the control group (P<0.05). Group 1 had a significantly higher number of repairable fractures than the other four groups (P<0.001). Within the limitations of this study, the results suggest that fibre posts can be recommended as an alternative to cast and prefabricated metallic posts. Composite resin cement cannot significantly improve fracture resistance of metallic post and crown-restored incisors.     

不同水门汀黏接树脂嵌体对牙体抗折力影响的研究

目的评价不同的水门汀黏接树脂嵌体后,牙体抗折力的差异。方法选20颗健康的上颌前磨牙,在面制备近远中邻洞(MOD洞)并作树脂嵌体,分为4组:A组(玻璃离子水门汀,GIC);B组(聚羧酸锌水门汀);C组(树脂加强型玻璃离子水门汀,RRGIC);D组(树脂水门汀,ARC)黏接树脂嵌体。样品经37℃水浴72h;5-55℃水浴循环2500次后,用振动动态测试系统进行抗折实验。结果RPGIC组与ARC组的抗折力高于GIC组和聚羧酸锌水门汀组;RPGIC组与ARC组之间无显著差异;GIC组和聚羧酸锌水门汀组之间无显著差异。结论RPGIC可以成为替代ARC的一种理想选择。     

Aspects of bonding between resin luting cements and glass ceramic materials

Objectives

The bonding interface of glass ceramics and resin luting cements plays an important role in the long-term durability of ceramic restorations. The purpose of this systematic review is to discuss the various factors involved with the bond between glass ceramics and resin luting cements.

Methods

An electronic Pubmed, Medline and Embase search was conducted to obtain laboratory studies on resin–ceramic bonding published in English and Chinese between 1972 and 2012.

Results and discussion

Eighty-three articles were included in this review. Various factors that have a possible impact on the bond between glass ceramics and resin cements were discussed, including ceramic type, ceramic crystal structure, resin luting cements, light curing, surface treatments, and laboratory test methodology.

Conclusions

Resin–ceramic bonding has been improved substantially in the past few years. Hydrofluoric acid (HF) etching followed by silanizaiton has become the most widely accepted surface treatment for glass ceramics. However, further studies need to be undertaken to improve surface preparations without HF because of its toxicity. Laboratory test methods are also required to better simulate the actual oral environment for more clinically compatible testing.     

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提要：纤维桩-树脂核-冠修复体越来越多用于口腔修复中。树脂核-冠间的黏结力是全冠获得固位力的主要因素之一,而树脂核-水门汀间黏结强度对冠黏结力的获得具有重要影响。本文就树脂成核材料及其临床应用,影响树脂核-水门汀间黏结强度的因素做一综述。     

Effects of refractive index solutions on the color of different luting cements

Abstract

Purpose. The purpose of this study is to determine the effects of refractive index solutions on the color of different luting cements at different periods. Materials and methods. Fourteen disc-shaped specimens were prepared for three different universal shade luting cements. All specimens were divided into two groups and a phthalate ester and glycerol refractive index solution was applied to the specimens at different periods. Color differences (ΔE*) were calculated for before and after 5, 15, 60 min and 24 h periods of applying refractive index solutions. Data were analyzed with multiple analysis of variance (ANOVA) and mean values were compared by the Tukey HSD test (α = 0.05). Results. Periods and periods–cement interaction were statistically significant (p ≤ 0.05). There was no statistically significant difference between the mean ΔE values of refractive index solutions and cement groups (p > 0.05). Conclusion. Refractive index solutions affected the color of luting cements.     

Evaluation of fracture resistance of endodontically treated maxillary premolars, restored with ceromer or heat-pressed ceramic inlays and fixed with dual-resin cements

The aim of this study was to evaluate the fracture resistance of endodontically maxillary premolars restored with mesio-occlusal-distal (MOD) inlays made with ceramic (IPS-Empress 2) and ceromer (Targis) and luted with three different dual-cured resin cements (Enforce, Variolink II, Panavia F). Sixty maxillary premolars were randomly distributed into six groups, according to their mesio-distal and facio-lingual dimensions. The teeth were endodontically treated and MOD cavities prepared. After the restorations were cemented, the samples were thermocycled and submitted to an axial compressive load by the action of a rounded end steel cylinder contacting the incline planes of occlusal surfaces of the teeth. The mode of fracture was analysed with a microscope. The best results were found with the combinations (cement/restorative material) Enforce/Targis (107.57 kgf) and Enforce/Empress (90.21 kgf) followed by Variolink II/Targis (86.44 kgf)-Variolink II/Empress (84.07 kgf) and Panavia F/Targis (82.43 kgf)-Panavia F/Empress (76.73 kgf). Analysis of variance (P < 0.05) showed a significant difference between Enforce and Panavia cements regardless of the restorative material. Considering the same luting agent there was no statistically significant difference between the restorative materials. Fracture of lingual cusps occurred in 55 of the 60 teeth and most of them were of the cohesive type.     

Effect of storage media and time on the fracture toughness of resin-based luting cements

Background: Resin‐based cements are brittle materials and the major shortcomings of these materials are manifested in their sensitivity to flaws and defects. Although various mechanical properties of resin luting cements have been described, few fracture toughness test data for resin‐based luting cements using the short rod design have been published. Methods: Specimens were prepared from five resin luting cements. For each material a total of 36 disc‐shaped specimens were prepared using a custom‐made mould. Specimens were randomly divided into six groups of six, immersed in two solutions: distilled water and 0.01 mol/L lactic acid at 37 °C for 24 hours, 1 month or 3 months. The specimens were loaded using a universal testing machine. The maximum load at specimen failure was recorded and the K_Ic (MPa. M 0.5) was calculated. Results: There was a relationship between material, storage solution and time (p < 0.05). Nexus 3 showed the highest K_Ic followed by Panavia F, Calibra, Smart Cem2 and seT. Conclusions: The fracture toughness of the resin luting cements was affected by both time and storage solution. Comparable fracture toughness of conventional resin cement and self‐adhesive resin cements was observed.     

Effect of an acidic sodium salt on the polymerization behavior of self-adhesive resin cements formulated with different adhesive monomers

Objective

To determine the influence of benzenesulfinic acid sodium salt 98% (BAS) and the activation mode on the polymerization behavior of experimental self-adhesive resin cements (SARCs) formulated with distinct self-etch methacrylates.

An in vitro study of the compressive load at fracture of Procera AllCeram crowns with varying thickness of veneer porcelain

STATEMENT OF PROBLEM: When designing and cutting a crown preparation, a balance must be achieved between the amount of tooth structure conserved and the space created for the restoration. All-ceramic crowns, which contain a core, are usually veneered with porcelain to produce the desired aesthetics and contour. The effect of veneer porcelain on the strength of the restoration has been a cause of debate. PURPOSE: The purpose of this study was to investigate the effect of different thickness of veneer porcelain on the compressive load at fracture of Procera AllCeram crowns. MATERIAL AND METHODS: Sixty brass dies were fabricated with a crown-like preparation and a chamfer margin. Sixty crowns were fabricated with a 0.6-mm-thick core: Procera crowns with either a 0.4-mm- or 0.9-mm-thick veneer of AllCeram (Groups 1 and 2 respectively) and In-Ceram crowns with a 0.9-mm-thick veneer of Vitadur Alpha porcelain (Group 3). Each group consisted of 20 crowns. In-Ceram crowns were used as the control group. All crowns were measured at 4 axial and 1 occlusal random locations before autoglazing. They were air abraded and adhesively bonded onto the appropriate brass die using Clearfil Newbond Bonding Agent, Clearfil Porcelain Bond Activator, and Panavia 21 TC Dental Adhesive as the luting agent. After storage in distilled water at 37 degrees C for 24 hours, the specimens were placed in a compressive test rig within an Instron universal testing machine and loaded in the center of the occlusal surface with a 4-mm diameter stainless steel ball. An axial preload of 20 N was applied before compressive testing at a crosshead speed of 0.1 mm/minute until fracture occurred. An analysis of variance revealed no significant difference in the load at fracture between the 3 groups (P=.3). Using a Bonferroni correction, independent t tests revealed no significant difference in load at fracture for any of the pair-wise comparisons between the 3 test groups (P < .05). RESULTS: The mean load at fracture for Group 1 was 2197.6 N (SD = 776.4); Group 2, 2401.4 N (SD = 699.1); and Group 3, 2581.0 N (SD = 715.6). CONCLUSION: Within the parameters of this study, the axial thickness of veneer porcelain did not have a significant effect on the compressive load at fracture of Procera AllCeram crowns.     

An in vitro study to investigate the load at fracture of Procera AllCeram crowns with various thickness of occlusal veneer porcelain

PURPOSE: The aim of this study was to investigate the effect of occlusal veneer porcelain thickness on the load at fracture of Procera AllCeram crowns. MATERIALS AND METHODS: Fifty resin dies were manufactured to incorporate the features of an all-ceramic crown preparation on a premolar tooth. Fifty corresponding crowns were constructed and divided into five groups. Groups 1, 2, 3, and 4 were crowns with 0.6-mm-thick Procera cores and 0.4-mm-thick axial veneer porcelain and occlusal veneer porcelain thicknesses of 0.0 mm, 0.4 mm, 0.9 mm, and 1.4 mm, respectively. Group 5 specimens consisted of 0.6-mm-thick In-Ceram cores with 0.4 mm of axial porcelain and 0.4 mm of occlusal porcelain. The crowns were cemented onto their respective dies with a resin luting agent. Specimens were stored in distilled water at 37 degrees C for 24 hours prior to placing them in a universal testing machine and applying a controlled compressive load at a cross-head speed of 0.1 mm/min until fracture occurred. RESULTS: The mean loads at fracture were 419 N (group 1), 702 N (group 2), 1,142 N (group 3), 1,297 N (group 4), and 732 N (group 5). Statistical analysis revealed significant differences (P < .05) in the load at fracture between the groups, except for between groups 2 and 5. CONCLUSION: Increasing the thickness of the occlusal veneer porcelain increased the load at fracture for Procera AllCeram crowns. There was no significant difference in load at fracture between the Procera and In-Ceram crowns.     

Live cell imaging reveals different modes of cytotoxic action of extracts derived from commonly used luting cements

ObjectiveTo compare cytotoxicity of extracts derived from commonly used luting cements: Hoffmann’s Zinc Phosphate (ZPC), GC Fuji Plus Resin Modified Glass Ionomer (RMGIC) and 3 M ESPE RelyX Unicem Resin Cement (RC) on primary human gingival fibroblasts (HGFs).DesignHGFs were exposed to different concentrations of the ZPC, RMGIC and RC extracts. The cytotoxicity was assessed with the PrestoBlue Cell Viability Reagent and viable cells were counted by a haemocytometer using the trypan blue exclusion test. In order to determine the primary mechanism of the cell death induced by extracts from different luting cements, the real-time monitoring of caspase-3/-7 activity and membrane integrity of cells was employed.ResultsThe extracts from the RMGIC and ZPC decreased the metabolic activity and numbers of viable cells. Unexpectedly, the extracts from the RC evoked only small effects on the metabolic activity of HGFs with a decreasing number of viable cells in a dose-and time-dependent manner. The live cell imaging revealed that the apoptosis was the primary mechanism of a cell death induced by the extracts derived from the RMGIC, whereas the extracts from the RC and ZPC induced a cell death through a necrotic and caspase-independent pathway.ConclusionsThe apoptosis was the primary mechanism of the cell death induced by the extracts derived from the RMGIC, whereas the extracts from the RC and ZPC induced a cell death via a necrotic pathway. We suggest that metabolic assays commonly used to assess the cytotoxicity of luting cements should be validated by alternative methods.     

Influence of resin cements on cuspal deflection and fracture load of endodontically-treated teeth restored with composite inlays

Abstract

Objectives. To evaluate the influence of resin cements on cuspal deflection, fracture load and failure mode of endodontically-treated teeth restored with composite resin inlays. Materials and methods. Forty maxillary premolars were randomly divided into four groups: G1 (sound teeth, control), G2 (RelyX ARC), G3 (RelyX Unicem) and G4 (Maxcem Elite). The teeth from groups 2, 3 and 4 received mesial-occlusal-distal preparations and endodontic treatments. Impressions were taken with vinyl polysiloxane and poured using type IV die stone. Inlays with Z250 composite resin were built over each cast and luted with the resin cements. A 200-N load was applied on the occlusal surface and the cuspal deflection was measured using a micrometer. The specimens were then subjected to an axial load until failure occurred. The resulting failure mode was analyzed. Results. The means for cuspal deflection (μm) and fracture load (N) followed by the same letter represent no statistically significant difference based on ANOVA and Tukey's test (p < 0.05). Cuspal deflection: G1 = 4.7 (±1.7)^a, G2 = 12.0 (±8.9)^a, G3 = 39.0 (±27.0)^b and G4 = 56.8 (±18.2)^b. Fracture load: G1 = 1982 (±893)^a, G2 = 690.9 (±225.5)^b, G3 = 679 (±193.6)^b and G4 = 465.5 (±121.6)^b. G1 presented cusp fractures only at the cement–enamel junction (CEJ). There was a high frequency of cusp fractures below the CEJ in G2, G3 and G4. Conclusions. Composite resin inlays luted with resin cements do not recover the strength of sound teeth. However, teeth restored with composite resin inlays and luted with RelyX ARC can withstand mechanical fatigue longer before failure occurs than those luted with RelyX Unicem and Maxcem Elite.     

Effect of surface treatment on the initial bond strength of different luting cements to zirconium oxide ceramic

The objective of this study was to compare the shear bond strength to zirconium oxide ceramic of adhesive-phosphate-monomer-containing (APM) and non-APM-containing (nAPM) luting cements after different surface treatments. nAPM cements: Bifix QM, Dual Cement, Duo Cement Plus, Multilink Automix, ParaCem Universal DC, PermaCem Smartmix, RelyX ARC, Variolink Ultra, and Variolink II; APM cements: Panavia EX, Panavia F2.0, and RelyX UniCem. Groups of ten test specimens were each prepared by layering luting cement, using cylindrical Teflon molds, onto differently treated zirconium dioxide discs. The surface treatments were airborne-particle abrasion with 110 μm alumina particles, silica coating (SC) using 30 μm alumina particles modified by silica (Rocatec System) or SC and silanization. Bifix QM and Multilink Automix were used in combination with an additional bonding/priming agent recommended by the manufacturers. After 48 h of water storage, each specimen was subjected to a shear test. Combinations involving APM-containing cements (14.41–23.88 MPa) generally exhibited higher shear bond strength than those without APM (4.29–17.34 MPa). Exceptions were Bifix QM (14.20–25.11 MPa) and Multilink Automix (19.14–23.09 MPa) in combination with system-specific silane or priming agent, which were on the upper end of shear bond strength values. With the use of the Rocatec system, a partially significant increase in shear bond strength could be achieved in nAPM cement. Modified surface treatment modalities increased the bond strength to zirconium oxide, although the most important factor in achieving a strong bond was the selection of a suitable cement. System-specific priming or bonding agents lead to further improvement.